Mr. Adams, the second black mayor in the city’s history, has been sworn in to use a family Bible his son Jordan Coleman kept and clutched a framed photo of his mother Dorothy, who died last spring.
As Mr. Adams left the stage, he announced, “New York is back.”
Mr de Blasio also attended the Times Square ceremony and danced on stage with his wife after leading the midnight countdown – his final act as mayor after eight years in office.
Mr Adams, who grew up poor in Queens, represents a center-left brand of democratic politics. He could offer a mix of the last two mayors – Bill de Blasio, who was known for quoting the socialist Karl Marx, and Michael R. Bloomberg, a billionaire and former Republican like Mr. Adams.
Mr Adams narrowly won a competitive Democratic primary last summer when coronavirus cases were low and millions of New Yorkers were vaccinated. The city had started to slowly recover after the virus devastated the economy and killed more than 35,000 New Yorkers. Now that cases are picking up again, Manhattan businesses have abandoned their return to office plans and many Broadway shows and restaurants have closed.